title: Genetic structure and variability of the endemic and vulnerable Vellozia gigantea (Velloziaceae) associated with the landscape in the Espinhaço Range, in southeastern Brazil: implications for conservation.
abstract: The Espinhaço Range, in eastern Brazil, has a peculiar landscape that has influenced the vegetation pattern of the region because of its valleys, canyons, ranges and disjunct rock outcrops found at high elevations. In this region, the vegetation type known as campos rupestres (rupestrian fields), which occurs in the disjunct outcrops, has high levels of species richness and endemism. Vellozia gigantea, a 6-m tall dracenoid monocot, is a vulnerable species endemic to this vegetation and has a narrow distribution that extends approximately 27 km. This region is located in a disturbed area, where populations are divided into three geographical groups, separated by a canyon and a valley. For this study, we used ISSR markers to measure the genetic diversity of the species and test the hypothesis that the canyon and the valley constitute geographical barriers to gene flow in V. gigantea. Nine populations and 173 individuals were analyzed using nine ISSR primers, which produced 89 fragments. In spite of being a vulnerable species with a narrow distribution, the populations of V. gigantea have high genetic diversity (mean percentage of polymorphic loci = 56.6%; mean Shannon's index of diversity = 0.278; mean expected heterozygosity = 0.183). Genetic divergence among populations was high (Φ(ST) = 0.28), and principal coordinate, neighborjoining and Bayesian analyses showed that only the canyon may constitute a partial barrier to gene flow in this species. Groups of populations separated by the canyon should be managed separately because they contain different gene pools.
authors.affiliation: Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Caixa Postal 486, Belo Horizonte, MG 31270-901, Brazil.
authors.forename: Júnia Maria
authors.initials: JM
authors.lastname: Lousada
authors.forename: Eduardo Leite
authors.initials: EL
authors.lastname: Borba
authors.forename: Katia Torres
authors.initials: KT
authors.lastname: Ribeiro
authors.forename: Leonardo Cotta
authors.initials: LC
authors.lastname: Ribeiro
authors.forename: Maria Bernadete
authors.initials: MB
authors.lastname: Lovato
mesh_terms: D001499:Bayes Theorem; D001938:Brazil; D016000:Cluster Analysis; D003247:Conservation of Natural Resources; D051456:Gene Flow; D014644:Genetic Variation / Q000235:genetics*; D005843:Geography; D019684:Magnoliopsida / Q000235:genetics*